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TRAINING IMPLICATIONS OF STRIDE LENGTH ANALYSIS

By Jack Farrell, XC/Track Coach, Thousand
Oaks High School, CA

Farrell shows why he is
one of the best. ..he does his homework. Have any readers done similar studies
on their athletes ? From what I read, Farrell just used a video camera and shows
how a simple analysis can lead to some very helpful conclusions about running.
If you weren't sure why Thousand Oaks has one of the top teams in the country,
now you know the rest of the story. Thanks to George Payan of California Coaches
Alliance for sending this article in.

In
1992 I attended the Junior Elite Distance Camp at Colorado Springs. The featured
presenter was Dr. Jack Daniels and one concept he introduced to us I found very
intriguing. He said that stride frequency was fairly fixed and idiosyncratic for
each runner-that no matter the pace, the frequency was nearly the same, and
that, as a runner increased his pace, the variable was stride length. In other
words, the runner increased the length of his stride while maintaining the same
basic turnover. He claimed that he and his assistants had done exhaustive stride
counts at meets to verify this.
This topic did not generate much discussion but I felt its implications were
enormous for training principles. I had already switched from a hard- easy
training regimen to a balanced one and had relied during cross country season
on what we called pick-up runs, but Daniels' claim formed the theoretical basis
for what we were already doing. Our balanced system called for lactate threshold
runs, or tempo runs, virtually every day.
A few principles became clear to me as a result of this theory:

The motion of running, at its most elemental level, is really jumping, or a
series of controlled bounces.

Increased oxygen uptake would allow a runner to sustain a longer bounce
with each stride.

This is the reason elite
runners, for instance 2:10 marathoners traveling
at 4:50 mile pace, look like they are running so easily. In point of fact, their
turnover is not significantly different from the 2:36 marathoner who is running 6:00 pace. Their superior oxygen uptake systems allow for a correspondingly
elongated stride-a bigger bounce, if you will.

Conventional wisdom has always cautioned against working on stride length
for fear of over striding. In actuality, few runners can even accomplish that
flaw. Most runners naturally foot-plant under their center of gravity. The
longer stride is accomplished by jumping farther with each push-off, not by
throwing the foot ahead of the center of gravity.

What allows this longer bounce to develop is increased leg strength,
increased flexibility and increased oxygen uptake. Of these three factors,
the increase in oxygen uptake is the most significant.

I have been studying running videos for years now in an attempt to verify some
of these principles. Most recently, I had occasion to count strides for Kim
Mortensen, the athlete I coached at Thousand Oaks H.S., who last year won the
Foot Locker National Cross Country title and set a new national interscholastic
record for 3200 meters of 9:48.59. I counted her strides during a training run
at 6 minutes/mile pace, during several portions of her second run, during a few
portions of her race the following week against Julia Stamps at the
International Prep Invitational in Elmhurst, Illinois.
I found that in training Kim took 194 strides per minute at 6 minutes per mile
pace. Kim's stride was there- fore 4'71/2" (or 541/2"). In order to drop her
pace from 6:00 minutes per mile in training to 4:55 during her record run, Kim
only increased her stride turnover by a factor of 3% to 200 strides per minute.
That necessitated an increase of 17% in her stride length to 5' 5 1/4" (65
1/4"). In order to drop her last quarter under 70 seconds and her last 200 to .34.3,
Kim's stride frequency only increased by a factor of another 2% to 204 strides
per minute, but her stride length increased by only 1.1% to 5' 6" (66"). This
suggests that, at least for Kim, she was already at near maximum stride length
to be sustained with available oxygen reserves and any increase in pace would
have to come from stride frequency, again at virtual max.
I also counted Julia Stamps' strides during the middle of the state meet 3200.
She took 10 fewer strides per minute than Kim, 190 versus 200, while maintaining
her position just behind Kim. Her stride in competition, therefore, was
somewhat longer than Kim's, 5' 8" per stride vs. 5' 5 1/4" per stride, demonstrating the idiosyncratic nature of this information. This would only have
significance if we knew Julia's stride frequency and length during normal
training runs. Also, Julia slowed down some 25 seconds during the last 1200
meters. It would be interesting to chart the impact this deceleration had on
both stride frequency and stride length. However, the camera remained on Kim and
thus I could not count Julia's strides.
One week later, Kim raced the mile at the International Prep Invitational and
ran 4 :47.73. Her stride pattern matched her kick of the Masters Meet, or 204
strides per min. However, her stride length dropped to 5' 4 3/4" (64 3/4"). It
took an extra 4 strides per minute at nearly the same length to drop her pace
from 4:54 to 4:48, approximately. She did increase her tempo slightly, without a
concomitant lengthening of her stride. I still feel the 4:48 was submaximal and
would posit that a steep drop in time, say to the low 4:40's, would necessitate
at least a moderate lengthening of the stride.
One of the reasons that Kim was so consistent in racing was that her training
was extremely consistent. She ran virtually every day at 6:00 pace all spring.
When it came time to race, she was physiologically prepared to make the
improvements described above. When a training system calls for vast
variations in pace, as the hard-easy system does, it may be more difficult to
achieve consistency in racing.
The question comes to mind: what is the best way to prepare for the stride
length increases necessitated by racing? Logically, more speed work, form
drills, and plyometrics seem to be in order. Ironically, these activities have
little to do with increasing oxygen uptake. A steady diet of 85% runs, about 1:00 per mile above 5K race pace, seems to produce the most dramatic results in
oxygen uptake efficiency.
At Thousand Oaks we use long intervals to simulate race pace and avoid virtually
all speedwork during cross country. The most common interval is 1320 yards, or
one-quarter of the 3-mile racing distance. We try to run these at race pace. For
instance, a 16-min. 3-miler would run 4:00 reps. We usually do four repetitions,
which is equal to the racing distance. Highly fit runners need a timed rest of
from 60-90 seconds to hold to race pace. Otherwise, with full rest (4- 7
minutes) they tend to run considerably under race pace. This training is more
race simulation and pace work than anything else.
We run these intervals every other Wednesday. On the alternate Wednesday we do
what we call a pick-up run. This is similar to a surge run, but there is no
backing off of the pace. In a typical 6- or 7-mile run, we designate a point
11/2 to 2 miles from the finish as the pick-up point. Athletes are asked to
drop the pace incrementally over the remainder of the run. The general
directive is to drop the pace until you are uncomfortable and hold it until you
are comfortable, and then drop it again. Runners usually drop the pace about
5-10 seconds per mile and then hold the pace for 45 seconds to a minute before
they attempt another drop. A given runner might experience a half a dozen drops
in pace before the end and may reach race pace with a half-mile or less to go
and even exceed race pace for the last few hundred yards. Fit runners find this
workout very stimulating. I think I now understand why it works.
A runner like Kim traveling at 6 min. pace and 83% of her maximum stride length
would experience discomfort when dropping the pace and increasing her stride
length. But more oxygen capacity is available and so within a brief period of
time she is now striding again at her normal turn- over, but with elongated
strides and deeper breathing. A state of homeostasis would be regained until
the next drop in pace.
When oxygen capacity is reached and stride length is
maximized, only then would the discomfort remain. This usually coincides with
the end of the training run or the end of the race. The pick-up run transitions
the body thought the lengthening of stride from training pace to race pace. At
training pace (6:00 per mile) and race pace (sub-5:00 per mile) the athlete
would look about the same: same cadence, same breathing. The difference would be the length of the
stride and the depth of the breathing.
At least for Kim, the number 83 seems significant. She trains at both 83% of her
race pace and also 83% of her stride length. Exercise physiologists talk of
the percentage of maximal oxygen uptake and the percentage of maximum heart rate
in training. As a coach I do very little in trying to determine these
values. It would be interesting to see what percentage Kim is training and
racing at in these two areas.
All of these results are tentative and self-correcting as I
make more observations. And I do plan to continue examining future runners and the
adjustments they make to move from training pace to race pace. It was my main
intent to open dialogue on this important training issue.